What GEM ENGINEERING LTD does

GEM Engineering and Maintenance Services Ltd, trading as FJN GEM, is a UK-based industrial engineering fabrication company headquartered at Deva Industrial Park, Sandycroft, Flintshire, with a dedicated Heat Exchangers and Piping unit on the same site and a Machine Shop in Maltby, Rotherham. Founded in 1974 and tracing its lineage through predecessor firms including Caxios, Janus Neill, Fabricom, GDF SUEZ, MTM Machining, and FJN, the company operates a ~50-year industrial platform serving enterprise clients across Oil & Gas, Power & Energy, Pharmaceutical, Food Production, Chemical & Petrochemical, Aerospace, Automotive, Nuclear, and Renewables sectors.

The core technical offering centers on shell and tube heat exchanger design, manufacture, and refurbishment to TEMA, PD 5500, and ASME VIII standards — the company's stated flagship capability — supplemented by plate heat exchangers, pressure vessels, piping systems, structural steelwork, precision CNC machining of tube sheets and flanges, off-site modular construction, and on-site maintenance and turnaround services. Underlying processes include MIG, TIG, and arc welding covered by an extensive third-party approved WPQR portfolio to ASME and EN standards, specialized calibrated tube expansion equipment, and ISO 9001:2015 / BS EN 1090 / PED-compliant quality systems.

Revenue is generated through quote-based project engagements (one-time manufacturing) and professional services for maintenance turnarounds, distributed exclusively via direct enterprise field sales with no reseller or marketplace channels. Pricing is opaque and entirely project-specific, with 24/7 emergency response positioned as a differentiator. The company markets itself as a "Partner of Choice" for engineering, procurement, fabrication, and construction services and does not disclose financials, headcount, or named customers in the available source material.

Name

GEM ENGINEERING LTD

Legal name

Gem Engineering and Maintenance Services Ltd

Website

https://gemengineering.co.uk

Company type

Private

Founded year

1974

Operating status

Operating

Headcount range

11–50 employees

Short description

FJN GEM is a UK-based industrial engineering fabrication company manufacturing shell and tube heat exchangers, pressure vessels, piping systems, steelwork, and modular assemblies to ASME/TEMA/PED standards. It serves enterprise clients across Oil & Gas, Power, Chemical, Pharmaceutical, Food, Aerospace, and Renewables sectors via direct quote-based project engagement.

Ownership category

akta.pro rank

Product category

Industrial Engineering Fabrication

NAICS

Power Boiler and Heat Exchanger Manufacturing (332410), Plate Work and Fabricated Structural Product Manufacturing (33231), Fabricated Pipe and Pipe Fitting Manufacturing (332996)

SIC

Fabricated Plate Work (Boiler Shops) (3443), Miscellaneous Fabricated Metal Products (3490)

akta.pro primary industry

Pressure Vessels, Columns & Storage Tanks (ASME/Process Vessels) (IMAHAEAF)

akta.pro secondary industry

Process Skids & Modular Process Systems (Packaged Units) (IMAHAEAH)

Keywords

• Industrial fabrication services
• Shell tube heat exchangers
• Pressure vessel manufacturing
• Industrial piping systems
• Maintenance turnaround services

Headquarters

HQ city

Doncaster, England

HQ country

United Kingdom

HQ region

Europe

Offices3 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Supply Chain, Operations, Infrastructure, Technology or R&D

Revenue model

1. Heat Exchanger Manufacturing and Refurbishment: Design, manufacture, supply, and refurbishment of shell and tube heat exchangers to PD 5500, ASME VIII, and TEMA standards. Includes re-tubing services and emergency stock tube inventory.
2. Steel Fabrication and Manufacturing: Custom design and manufacture of metal works including structural steelwork, platforms, steps, staging, industrial tooling storage and trolley transport, and general fabrication. Materials include stainless steel, mild steel, aluminium, brass, and copper.
3. Pressure Vessel Supply: Full mechanical design and manufacture of pressure vessels to PD 5500 and ASME VIII standards, fully PED compliant. Materials include austenitic stainless steels, cupro nickel alloys, duplex stainless steel, brass, and chrome molybdenum.
4. Piping Systems: Design, supply, manufacture, and testing of pipework systems to internationally recognized standards including ISO 9001 quality systems. Applications include service/process pipework, fire deluge systems, buried pipework, lined systems, and high pressure/purity systems.
5. Maintenance and Turnaround Services: Execution of major turnaround events, single unit shutdowns, and routine daily maintenance services including planning, procurement, subcontract management, skilled technicians provision, asset replacement/refurbishment, and commissioning support.
6. Modular Construction: Off-site construction of piping systems, steelwork, and modules including PAU/PAR, DRV, skid units, and structural steel assemblies. Modules transported within UK and worldwide.
7. Site Services: Immediate response to client requirements including 24-hour emergency service, installation of plant and equipment, and construction support.
8. Machining Services: Precision machining including tube sheets, flanges, and drilling services.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels7 records

Core offering

FJN GEM designs, manufactures, refurbishes, and installs shell-and-tube and plate heat exchangers, pressure vessels, industrial piping systems, and structural steelwork, complemented by precision CNC machining, modular skid construction, and on-site maintenance and turnaround services for industrial clients. Operations are accredited to ISO 9001:2015 and BS EN 1090, with full PED, PD 5500, ASME VIII, and TEMA compliance.

Product overview

FJN GEM (trading as GEM Engineering and Maintenance Services Ltd) is a traditional engineering fabrication company with approximately 50 years of lineage. The company operates a platform of interconnected manufacturing and service offerings rather than a unified software product. The core portfolio includes Shell & Tube Heat Exchangers (including Plate Heat Exchangers), Pressure Vessels, and Piping Systems as primary manufactured products, complemented by Steel Fabrications, Machining Services, and Modular Construction capabilities. Service operations include Construction & Installation Services, Site Services, and Maintenance and Turnaround Services. The company serves sectors including Oil, Gas, Power, Chemical, Petrochemical, Pharmaceutical, Food Production, Aerospace, and Renewables industries. All operations are quality assured to ISO 9001:2015 and BS EN 1090 standards.

Differentiator

Problem solved

Functional benefit

Products and services

• Shell & Tube Heat Exchangers Full TEMA shell and tube heat exchangers including fixed and floating head designs, vertical re-boilers, oil coolers, kettle re-boilers, fin-fan air coolers, repairs, and re-tubing services. Manufactured to PD 5500, ASME VIII, and TEMA standards for Oil, Gas, Power, Petrochemical, Pharmaceutical, and Food industries.
• Plate Heat Exchangers
• Pressure Vessels
• Piping Systems
• Steel Fabrications
• Machining Services
• Modular Construction
• Construction & Installation Services
• Maintenance and Turnaround Services
• Site Services

Segments9 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Scale indicators1 record

Recent moves5 records

Expansion highlights5 records

Broad incumbents

• Holtec International: US-headquartered supplier of heat exchangers, pressure vessels, and nuclear-grade components built to ASME codes. Overlaps with FJN GEM on ASME heat exchanger and pressure vessel manufacturing, especially for power and nuclear customers.
• Goodwin plc: UK-based steel casting and engineering fabrication business serving power, oil & gas, and industrial markets with complex cast and fabricated components. Comparable UK industrial engineering heritage and customer verticals.
• Hamworthy (Wärtsilä): Originally a UK Poole-based engineering company (now part of Wärtsilä) historically known for marine and industrial heat exchangers and pressure equipment. Comparable legacy in ASME heat exchanger manufacturing for marine, oil & gas, and power applications.
• Alleima: Global materials and engineering company (formerly Sandvik Materials Technology) producing pressure vessel and heat exchanger tubes plus fabricated equipment. Overlaps with FJN GEM on materials expertise (duplex, super duplex, austenitic stainless) used in shell & tube exchangers.
• Petrofac: UK-listed EPC and operations services contractor for the oil & gas, refining, and energy transition sectors with in-house process equipment fabrication and modular construction. Overlaps with FJN GEM's modular-skid and pressure-equipment capabilities.
• Bilfinger: European industrial services provider with extensive process plant EPC and maintenance capabilities including heat exchangers, pressure vessels, and piping systems across petrochemical, energy, and process industries. Strong functional overlap with FJN GEM's EPFC offering.
• Babcock International: UK-headquartered engineering services group operating nuclear, defence, and industrial EPC programmes with significant in-house fabrication and code-compliant pressure equipment capability. Comparable UK nuclear/industrial customer base and PED/ASME compliance focus.
• Chart Industries: Global manufacturer of cryogenic and process heat exchangers, brazed aluminum heat exchangers, and process equipment. Directly comparable product overlap with FJN GEM's shell & tube heat exchanger focus, but at vastly larger scale and broader geographic footprint.
• Worley: Global energy, chemicals, and resources project delivery and maintenance provider with fabrication and modular construction capabilities. Comparable EPC and modular-skid positioning with overlapping oil & gas, power, and renewables verticals.
• Senior plc: UK-listed engineering group with aerospace and industrial fluid conveyance divisions, including heat transfer and fabricated assemblies. UK-based platform with multi-sector industrial customers comparable to FJN GEM's served verticals.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks5 records

Key highlights6 records

Customer concentration

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Compliance11 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about GEM ENGINEERING LTD